More Cryptic Messages To Sniper

The police chief of Montgomery County, Maryland, has issued a new appeal to the person believed to be the Washington-area sniper.

In an evening news briefing, the police chief suggested authorities had been in repeated contact with the sniper.

"We have researched the options you stated and found that it is not possible electronically to comply in the manner that you requested," he said. "However, we remain open and ready to talk to you about the options you have mentioned."

He said the sniper is seeking an 800 telephone number to talk with authorities, and offered to set up a private post office box "or another secure method."

"You indicated that this is about more than violence," Moose said. "We are waiting to hear from you."

He refused to take questions from reporters.

Earlier Tuesday, police investigators revealed they had received a message warning, "Your children are not safe anywhere at any time."

The chilling warning was delivered in a letter discovered by police Saturday night. Sources tell CBS News the whole letter is three pages long and was found posted on a tree behind the restaurant where a shooting occurred Saturday night in the area of Richmond, Virginia. The Washington Post is reporting that the note found Saturday contained a demand for $10 million.

CBS News Correspondent Jim Stewart has learned government officials found information in this letter convincing them it is from the same person who left a tarot card at an earlier shooting scene. The poorly-worded, error-filled note also raises the possibility that English is not the sniper's first language, reports Stewart.

Early Tuesday, bus driver Conrad Johnson, 35, was shot and killed in the latest attack that bore the hallmarks of the serial sniper who has slain nine other people this month.

Not counting Johnson, 12 people have been shot by the sniper in Maryland, Virginia and Washington, D.C.; nine killed and three critically wounded.

Johnson, a father of two, was fatally wounded as he prepared for his morning bus route in suburban Aspen Hill, Maryland. He was shot as he stood at the top steps of his bus shortly before 6 a.m. He died later at a hospital.

"We don't know if this is related but we're treating this as if it is," said Montgomery County Police Capt. Nancy Demme.

Within minutes of the shooting, police closed many roads around the crime scene and set up roadblocks at points along the Capital Beltway. Teams of officers and FBI agents with automatic rifles slung over their shoulders, were checking all cars driven by men on the main roads leading out of Montgomery County, reports CBS News Correspondent Jim Axelrod.

The shooting happened near an apartment building and wooded area along Connecticut Avenue, one of the main arteries into Washington. The bus was parked at a staging area where drivers get ready for their morning runs, state police spokesman Cpl. Rob Moroney said. He didn't know if anyone else was on the bus.

Agents for the federal Bureau of Alcohol, Tobacco and Firearms combed the crime scene. A police dog searched near a basketball court in a park, and police helicopters flew over the scene.

The location is near the sites of the first six sniper attacks, all on Oct. 2 and 3. In all, 12 people have been shot in Maryland, Virginia and Washington, D.C.; three were critically wounded.

"We remain concerned about the safety of all the people in our region," Moose said Tuesday. "We realize that the person or the people involved in this have shown a clear willingness and ability to kill people of all ages, all races, all genders, all professions, different times, different days and different locations."

"I was getting ready to leave for work this morning. I heard a loud bang," said Kim Roberts, a carpenter who lives nearby. "It wasn't a pop like a handgun. If it was a gun, it was a high-powered weapon." He said he knew about the sound of weapons from his military service.

CBS Radio Affiliate WTOP reports another eyewitness said he heard three shots, which is unusual since the sniper has been known for firing only once.

Schools in the Richmond area, near Saturday's shooting, remained closed a second day Tuesday, but were scheduled to be open on Wednesday. School officials are urging communities to be "extremely vigilant" with their children before and after school.

In other developments: